Ceramic matrix composite materials are known for their strength and resistance to temperatures approaching 1,200° C. U.S. Pat. No. 6,197,424 describes the use of high temperature insulation with a ceramic matrix composite to extend the useful operating temperature of the CMC material for hot gas path components of a gas turbine engine. The patent describes a process wherein a casting of the insulating material is formed to its green body state. After removal from the mold, the green body is shaped to conform to the contour of a mating CMC substrate surface. The near net shape green body is fired to its fully stabilized state and then ground to a final shape for bonding to the substrate, such as with a ceramic adhesive. In a most preferred embodiment, the uncured green body is applied to an uncured substrate and the two materials are co-fired to form the final composite structure. It is important to achieve intimate contact between the CMC substrate and the insulating layer in order to maximize the integrity of the structure. Tolerance stack-up between the mating surfaces can complicate this bonding process.